Take the hook from your inventory and it should go red over the winch (the long wire by the jeep). It should attach itself.

Click on the attached hook and your cursor should now be in the shape of the hook, go over to the front part of the jeep. There's a metal ring at the front. Take the hook and place it there and the hook should attach to the jeep.

Head over to the machine and press the red button and it should activate the machine to lift the jeep out of the ditch.

I will admit that I am out of ideas. Maybe someone else will have a suggestion for you. Are you sure you are trying to attach the hook to the round metal attachment connected to the winch wire? I never heard any reports about the game being glitchy here, although of course there is a first time for everything. I would also suggest going over MaG's walkthrough step by step to make sure you haven't missed anything.